package com.itheima.demo1;

import java.math.BigInteger;
import java.util.Random;

public class BigIntegerDemo1 {

    public static void main(String[] args) {

        //获取一个随机的大整数
        java.math.BigInteger bd1 = new java.math.BigInteger(4,new Random());
        System.out.println(bd1
        );

        //获取一个指定的大整数
        java.math.BigInteger bd2 = new BigInteger("100");
        System.out.println(bd2);


        String s1 = "(([^<>()\\.:\\s@]+(\\.[^<>()\\.:\\s@]+)*)|(.+))@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\])|(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,}))";
        System.out.println("1235465456@qq.com".matches(s1));


        String rege = "((.)\\2*).+\\1";
        System.out.println("aaa123aba".matches(rege));

    }
}
